Growth in height and its association with overweight and obesity in Mexican children: an evaluation based on a nationally representative sample (ENSANUT 2018)

The present study aimed to estimate the height growth curve for Mexican boys and girls based on their body mass index (BMI) status (normal and overweight/obese) and to develop a height Lambda, Mu, and Sigma (LMS) growth reference for Mexican children aged 2 to 18 years.

Methods

Chronological age and height records (7,097 boys and 6,167 girls) were obtained from the Mexican National Survey of Health and Nutrition database. Height growth curves were fitted using the Preece-Baines 1 (PB1) model and the LMS method.

Results

Age at peak height velocity (APHV) was 12.4 and 12.7 years for overweight-obese and normal-weight boys, respectively, and was 9.6 and 10.4 years for overweight-obese and normal-weight girls, respectively. Growth velocity was higher at the age of take-off (TO) in overweight-obese children than in normal-weight children (5.2 cm/year vs. 5 cm/year in boys and 6.1 cm/year vs. 5.6 cm/year in girls); nevertheless, the growth velocity at APHV was higher for normal-weight children than for overweight-obese children (7.4 cm/year vs. 6.6 cm/year in boys and 6.8 cm/year vs. 6.6 cm/year in girls, respectively). Distance curves developed in the present study and by the World Health Organization (WHO) using LMS showed similar values for L and S parameters and a higher M value compared with the WHO reference values.

Conclusion

This study concluded that overweight-obese children had earlier APHV and lower PHV than normal-weight children. Furthermore, Mexican children and adolescents were shorter than the WHO growth reference by age and sex.

Testing the Institute of Medicine (IOM) recommendations on maternal reproductive health and associated neonatal characteristics in a transitional, Mediterranean population

BACKGROUND

High pre-pregnancy body mass index (BMI) and excessive gestational weight gain (GWG) are significant risk factors for maternal and neonatal health.

AIM

To assess pre-pregnancy BMI and GWG during pregnancy and their association with different maternal and neonatal characteristics in the transitional Mediterranean population from the Eastern Adriatic islands.

SUBJECTS AND METHODS

262 mother-child dyads from the CRoatian Islands' Birth Cohort Study (CRIBS) were included in the study. Chi-square test, ANOVA and regression analysis were used to test the association between selected characteristics.

RESULTS

22% of women entered pregnancy with overweight/obesity and 46.6% had excessive GWG. Pre-pregnancy overweight and obesity were significantly associated with elevated triglycerides uric acid levels, and decreased HDL cholesterol in pregnancy. Excessive GWG was associated with elevated fibrinogen and lipoprotein A levels. Women with high pre-pregnancy BMI and GWG values were more likely to give birth to babies that were large for gestational age (LGA), additionally confirmed in the multiple logistic regression model.

CONCLUSION

High maternal pre-pregnancy BMI and excessive GWG were both significantly associated with deviated biochemical parameters and neonatal size. More careful monitoring of maternal nutritional status can lead to better pre- and perinatal maternal health care.

Reproducibility of bone age assessment from DXA hand scans: expert versus novice

Dual-energy x-ray absorptiometry (DXA) scans are frequently used in human biological research to study bone health and body composition. Hand-wrist scans for the assessment of skeletal maturity can also be easily obtained in immature research participants who are being scanned to assess bone health. Whilst assessment by an expert is the desired arrangement such expertise may not be available, and thus knowledge of the relative reproducibility of a trained novice and an acknowledged expert is pertinent. Here we compare the relative reproducibility of an expert and a trained novice on 41 DXA left-hand scans of adolescent males using the Tanner-Whitehouse 3 (TW3) RUS method. The trained novice showed almost perfect reproducibility when evaluating bone age from DXA hand scans compared to an expert in skeletal maturity assessment. Both observers demonstrated reproducibility good enough to suggest that the TW3 method is appropriate to use with DXA hand scans by a trained researcher.

Stress, locus of control, hope and depression as determinants of quality of life of pregnant women: Croatian Islands' Birth Cohort Study (CRIBS)

The aims were to investigate determinants of the quality of life (QoL) of pregnant women. Total of 302 healthy women 18 to 28 weeks of gestation participated in prospective study. WHOQOL-bref, Multidimensional Health Locus of Control scales, Edinburgh Postnatal Depression Scale, and the perceived stress appraisals were administered. Various patterns of predictors for four domains of QoL were identified, for psychological (42% variance explained), social relationship (29%), environmental (29%) and physical health (25%). Depression and hope, together with the extent to which one's health is influenced by powerful other or chance should be targeted in health promotion strategies during pregnancy.

Utilizing auxology to understand ontogeny of extinct hominins: A case study on Homo naledi

The methods used to study human growth and development (auxology) have not previously been applied within the setting of hominin maturation (ontogeny). Ontogeny is defined here as the pattern of biological change into an adult form, both at the individual and species level. The hominin fossil record has a lack of recovered immature materials, due to such factors as taphonomic processes that destroy pre-adults; the fragility of immature compared to adult bone; and the lower mortality rates of juveniles compared to adults. The recent discovery of pre-adult hominin skeletal material from a single, homogeneous Homo naledi species from the Rising Star cave system in South Africa provides the opportunity for a broader application of auxology methods and thus the need to understand their use in a modern context. Human auxology studies benefit from a robust database, across multiple populations, and with longitudinal studies in order to assess the patterns and variations in typical growth, development and life history stages. Here, we review the approach, vocabulary, and methods of these human studies, investigate commonalities in data with the fossil record, and then advance the reconstruction of ontogeny for the extinct hominin species H. naledi. To this end, we apply an auxology model into the paleontological context to broadly predict H. naledi birthweight of the offspring at 2.06 kg with a range (±1 SD) of 1.89 to 2.24 kg, with a length at birth 45.5 cm. We estimate a H. naledi juvenile partial skeleton DH7 to be a height of 111-125 cm at death.

Investigating the relationship between fetal growth and academic attainment: secondary analysis of the Born in Bradford (BiB) cohort

Background

The relationship between ultrasongraphically derived estimates of fetal growth and educational attainment in the postnatal period is unknown. Results from previous studies focusing on cognitive ability, however, suggest there may be gestation-specific associations. Our objective was to model growth in fetal weight (EFW) and head circumference (HC) and identify whether growth variation in different periods was related to academic attainment in middle childhood.

Methods

Data come from the Born in Bradford (BiB) cohort study, which has performed data linkage to both routine antenatal scans and national academic attainment tests at age 6-7 years. Multilevel linear spline models were used to model EFW and HC. Random effects from these were related to Key Stage 1 (KS1) results in reading, writing, mathematics, science and a composite of all four (age 6-7 years), using ordinal logistic and logistic regression. Associations were adjusted for potential confounders, facilitated by directed acyclic graphs. Missing covariate data were imputed using multiple imputation.

Results

In all, 6995 and 8438 children had complete KS1, and EFW and HC data, respectively. Positive associations were observed between both fetal weight in early pregnancy (14 weeks) and EFW growth in mid-pregnancy (14-26 weeks) and the individual KS1 outcomes. Furthermore, after adjustment for previous size and confounders, a 1-z score increase in growth in mid-pregnancy was associated with an 8% increased odds of achieving the expected standard for all KS1 outcomes [odds ratio (OR): 1.08, 95% confidence interval (CI): 1.02; 1.13]. Similar results were observed for HC, with generally larger effect sizes. Smaller associations were observed with growth in the early-third trimester, with no associations observed with growth in the later-third trimester.

Conclusions

We observed consistent positive associations between fetal size and growth in early and mid-gestation and academic attainment in childhood. The smaller and null associations with growth in the early-third and later-third trimester, respectively, suggests that early-mid gestation may be a sensitive period for future cognitive development.

Palaeodemographics of individuals in Dinaledi Chamber using dental remains

Hominin skeletal remains from the Dinaledi Chamber, South Africa, represent a minimum of 15 individuals of the extinct species Homo naledi. We examined the dental material from this sample in order to assess the life-history stages of individuals in the sample, in particular to determine the minimum number of individuals in the sample as a whole, and within each of six age classes. We found evidence of individuals within every age class: infant, early juvenile, late juvenile, subadult, young adult and old adult. The Dinaledi Chamber sample is notable in comparison to other samples of human, chimpanzee and fossil hominins in that it has a relatively high representation of juvenile remains, as compared to infants and adults. With 15 individuals, the sample size presented by the Dinaledi dental material is too small to test the hypothesis of attritional versus catastrophic accumulation. The data here provide a basis for further investigation of individual associations within this commingled assemblage, and provide an important comparative data set as a basis for the consideration of life history in H. naledi and other extinct hominin populations.

Association of maternal exposures with adiposity at age 4/5 years in white British and Pakistani children: findings from the Born in Bradford study

AIMS/HYPOTHESIS

There is evidence that, from birth, South Asians are fatter, for a given body mass, than Europeans. The role of developmental overnutrition related to maternal adiposity and circulating glucose in these ethnic differences is unclear. Our aim was to compare associations of maternal gestational adiposity and glucose with adiposity at age 4/5 years in white British and Pakistani children.

METHODS

Born in Bradford is a prospective study of children born between 2007 and 2010 in Bradford, UK. Mothers completed an OGTT at 27-28 weeks of gestation. We examined associations between maternal gestational BMI, fasting glucose, post-load glucose and diabetes (GDM) and offspring height, weight, BMI and subscapular skinfold (SSF) and triceps skinfold (TSF) thickness at age 4/5 years, using data from 6060 mother-offspring pairs (2717 [44.8%] white British and 3343 [55.2%] Pakistani).

RESULTS

Pakistani mothers had lower BMI and higher fasting and post-load glucose and were twice as likely to have GDM (defined using modified WHO criteria) than white British women (15.8% vs 6.9%). Pakistani children were taller and had lower BMI than white British children; they had similar SSF and lower TSF. Maternal BMI was positively associated with the adiposity of offspring in both ethnic groups, with some evidence of stronger associations in Pakistani mother-offspring pairs. For example, the difference in adjusted mean BMI per 1 kg/m2 greater maternal BMI was 0.07 kg/m2 (95% CI 0.05, 0.08) and 0.10 kg/m2 (95% CI 0.09. 0.11) in white British and Pakistani children, respectively, with equivalent results for SSF being 0.07 mm (95% CI 0.05, 0.08) and 0.09 mm (95% CI 0.08. 0.11) (p for ethnic difference < 0.03 for both). There was no strong evidence of association of fasting and post-load glucose, or GDM, with outcomes in either group.

CONCLUSIONS/INTERPRETATION

At age 4/5 years, Pakistani children are taller and lighter than white British children. While maternal BMI is positively associated with offspring adiposity, gestational glycaemia is not clearly related to offspring adiposity in either ethnic group.

A comparison of skeletal maturity assessed by radiological and ultrasonic methods

OBJECTIVES

The estimation of skeletal maturity is a useful tool in pediatric practice to determine the degree of delay or advancement in growth disorders and the effectiveness of treatment in conditions that influence linear growth. Skeletal maturity of children is commonly assessed using either Greulich-Pyle (GP) or Tanner-Whitehouse methods (TW2 and TW3). However, a less invasive ultrasonic method, that does not use ionizing radiation, has been suggested for use in epidemiological studies of skeletal maturity. The main purpose of the present study was to determine the accuracy of an ultrasonic method based on the GP maturity indicators compared to the standard GP radiographic method.

METHODS

Skeletal maturity of 1502 healthy children, aged from 6 to 18 years, was estimated by quantitative ultrasound and compared to GP bone ages estimated from left hand and wrist radiographs of a subsample of 47 randomly selected participants.

RESULTS

The ultrasonic bone age estimation demonstrated very strong correlations with all the radiological age estimations. The correlation coefficients ranged between 0.895 and 0.958, and the strongest correlation of ultrasonic skeletal maturity estimation was found with the Tanner-Whitehouse RUS method. The ultrasonic bone age estimation is suggested for use between the chronological ages of 8.5-16.0 years in boys and 7.5-15.0 years in girls.

CONCLUSIONS

The ultrasonic bone age estimation is suggested for use in epidemiological surveys since the sensitivity for screening for not normal bone development is appropriate, at least within the 8-15 years age interval.

The postcranial skeletal maturation of Australopithecus sediba

OBJECTIVES

In 2008, an immature hominin defined as the holotype of the new species Australopithecus sediba was discovered at the 1.9 million year old Malapa site in South Africa. The specimen (MH1) includes substantial post-cranial skeletal material, and provides a unique opportunity to assess its skeletal maturation.

METHODS

Skeletal maturity indicators observed on the proximal and distal humerus, proximal ulna, distal radius, third metacarpal, ilium and ischium, proximal femur and calcaneus were used to assess the maturity of each bone in comparison to references for modern humans and for wild chimpanzees (Pan troglodytes).

RESULTS

In comparison to humans the skeletal maturational ages for Au. sediba correspond to between 12.0 years and 15.0 years with a mean (SD) age of 13.1 (1.1) years. In comparison to the maturational pattern of chimpanzees the Au. sediba indicators suggest a skeletal maturational age of 9-11 years. Based on either of these skeletal maturity estimates and the body length at death of MH1, an adult height of 150-156 cm is predicted.

DISCUSSION

We conclude that the skeletal remains of MH1 are consistent with an ape-like pattern of maturity when dental age estimates are also taken into consideration. This maturity schedule in australopiths is consistent with ape-like estimates of age at death for the Nariokotome Homo erectus remains (KMN-WT 15000), which are of similar postcranial immaturity to MH1. The findings suggest that humans may have distinctive and delayed post-cranial schedules from australopiths and H. erectus, implicating a recent evolution of somatic and possibly life history strategies in human evolution.

Development and evaluation of an intervention for the prevention of childhood obesity in a multiethnic population: the Born in Bradford applied research programme

Background

There is an absence of evidence about interventions to prevent or treat obesity in early childhood and in South Asian populations, in whom risk is higher.

Objectives

To study patterns and the aetiology of childhood obesity in a multiethnic population and develop a prevention intervention.

Design

A cohort of pregnant women and their infants was recruited. Measures to compare growth and identify targets for obesity prevention, sensitive to ethnic differences, were collected. A feasibility randomised controlled trial (RCT) was undertaken.

Setting

Bradford, UK.

Participants

A total of 1735 mothers, 933 of whom were of South Asian origin.

Intervention

A feasibility trial of a group-based intervention aimed at overweight women, delivered ante- and postnatally, targeting key modifiable lifestyle behaviours to reduce infant obesity.

Main outcome measures

The feasibility and acceptability of the pilot intervention.

Data sources

Routine NHS data and additional bespoke research data.

Review methods

A systematic review of diet and physical activity interventions to prevent or treat obesity in South Asian children and adults.

Results

Routine measures of growth were accurate. The prevalence of risk factors differed between mothers of white British ethnicity and mothers of Pakistani ethnicity and weight and length growth trajectories differed between Pakistani infants and white British infants. Prediction equations for risk of childhood obesity were developed. An evidence-based intervention was evaluated in a pilot RCT and was found to be feasible and acceptable.

Limitations

This was a single-centre observational study and a pilot evaluation.

Conclusions

The programme has been successful in recruiting a unique multiethnic childhood obesity cohort, which has provided new evidence about modifiable risk factors and biethnic growth trajectories. A novel group-based behavioural change intervention has been developed and successfully piloted. A multisite cluster RCT is required to evaluate effectiveness.

Trial registration

Current Controlled Trials ISRCTN56735429.

Funding

The National Institute for Health Research Programme Grants for Applied Research programme.

Beyond height and weight: a programme of school nurse assessed skinfold measurements from white British and South Asian origin children aged 4-5 years within the Born in Bradford cohort study

OBJECTIVE

To describe the feasibility, reliability and additional information gained from collecting additional body fatness measures (beyond height and weight) from UK reception year children.

DESIGN

Prospective cohort study.

SETTING

Bradford, UK.

PARTICIPANTS

2458 reception year children participating in the Born in Bradford (BiB) cohort study.

MAIN OUTCOME MEASURES

The feasibility and reliability of subscapular and triceps skinfold measurements and differences in adiposity between ethnic groups.

RESULTS

Of those children who were matched to their school, 91% had a subscapular skinfold measurement and 92% had a triceps skinfold measurement recorded. Reliability was generally over 90% for all measurers and both measurements. Pakistani children were slightly taller but weighed less and had lower triceps skinfold thickness (mean difference -1.8 mm, 95% CI -2.1 to -1.4 mm) but higher subscapular (mean difference 0.1 mm, 95% CI -0.1 to 0.4 mm) than white British children.

CONCLUSIONS

We have shown that it is feasible for school nurses to collect skinfold measurements in a similar way to the height and weight measurements collected from reception year children for the National Child Measurement Programme (NCMP), and that these measurements are reliable. It is important for healthcare practice to acknowledge ethnic-specific risk and these additional measurements can provide important information to examine population-level risk in populations with large proportions of South Asian children.

Homo naledi, a new species of the genus Homo from the Dinaledi Chamber, South Africa

Homo naledi is a previously-unknown species of extinct hominin discovered within the Dinaledi Chamber of the Rising Star cave system, Cradle of Humankind, South Africa. This species is characterized by body mass and stature similar to small-bodied human populations but a small endocranial volume similar to australopiths. Cranial morphology of H. naledi is unique, but most similar to early Homo species including Homo erectus, Homo habilis or Homo rudolfensis. While primitive, the dentition is generally small and simple in occlusal morphology. H. naledi has humanlike manipulatory adaptations of the hand and wrist. It also exhibits a humanlike foot and lower limb. These humanlike aspects are contrasted in the postcrania with a more primitive or australopith-like trunk, shoulder, pelvis and proximal femur. Representing at least 15 individuals with most skeletal elements repeated multiple times, this is the largest assemblage of a single species of hominins yet discovered in Africa.

A critical discussion of the Community Readiness Model using a case study of childhood obesity prevention in England

Recent reforms to the public health system in England aim to generate co-ordinated action between local authorities, healthcare systems and communities to target local health priorities. To support this effort, researchers must contribute and evaluate appropriate strategies for designing interventions tailored to community-specific needs. One strategy is to apply the Community Readiness Model (CRM), which uses key informant interviews to assess a community's readiness to address local issues. This article presents a critical discussion of the CRM developed from a case study of obesity prevention in pre-adolescent girls within a community in the United Kingdom. Data were collected between February and November 2011. We offer lessons learnt and recommendations relating to (i) modifications to the interview guide; (ii) key informant identification; (iii) conducting interviews to theoretical saturation; (iv) using key informants to define their community; (v) key informant's ability to respond on behalf of the community; (vi) using a qualitative model with a quantitative scoring system; and (vii) the optimum application of transcript scoring. In conclusion, the CRM can help researchers, health professionals and local authorities identify the priorities of a community. It is recommended that users of the model be careful to identify and recruit suitable key informants with the help of the community under study, select an appropriate 'community' and utilise the qualitative findings to strengthen the interpretation of the readiness score.

Stress fracture injury in female endurance athletes in the United Kingdom: A 12-month prospective study

Studies of stress fracture (SF) incidence are limited in number and geographical location; this study determined the incidence of SF injury in female endurance athletes based in the United Kingdom. A total of 70 athletes aged between 18 and 45 years were recruited and prospectively monitored for 12 months. Questionnaires at baseline and 12 months assessed SF, menstrual and training history, eating psychopathology, and compulsive exercise. Peak lower leg muscle strength was assessed in both legs using an isometric muscle rig. Bone mineral density (BMD) of total body, spine, hip, and radius was assessed using dual X-ray absorptiometry. Among the 61 athletes who completed the 12-month monitoring, two sustained a SF diagnosed by magnetic resonance imaging, giving an incidence rate (95% confidence intervals) of 3.3 (0.8, 13.1) % of the study population sustaining a SF over 12 months. The SF cases were 800 m runners aged 19 and 22 years, training on average 14.2 h a week, eumenorrheic with no history of menstrual dysfunction. Case 1 had a higher than average energy intake and low eating psychopathology and compulsive exercise scores, while the reverse was true in case 2. BMD in both cases was similar to mean values in the non-SF group. The incidence of SF in our female endurance athlete population based in the United Kingdom was 3.3%, which is lower than previously reported. Further work is needed to confirm the current incidence of SF and evaluate the associated risk factors.

Small-for-gestational age and large-for-gestational age thresholds to predict infants at risk of adverse delivery and neonatal outcomes: are current charts adequate? An observational study from the Born in Bradford cohort

OBJECTIVES

Construct an ethnic-specific chart and compare the prediction of adverse outcomes using this chart with the clinically recommended UK-WHO and customised birth weight charts using cut-offs for small-for-gestational age (SGA: birth weight <10th centile) and large-for-gestational age (LGA: birth weight >90th centile).

DESIGN

Prospective cohort study.

SETTING

Born in Bradford (BiB) study, UK.

PARTICIPANTS

3980 White British and 4448 Pakistani infants with complete data for gestational age, birth weight, ethnicity, maternal height, weight and parity.

MAIN OUTCOME MEASURES

Prevalence of SGA and LGA, using the three charts and indicators of diagnostic utility (sensitivity, specificity and area under the receiver operating characteristic (AUROC)) of these chart-specific cut-offs to predict delivery and neonatal outcomes and a composite outcome.

RESULTS

In White British and Pakistani infants, the prevalence of SGA and LGA differed depending on the chart used. Increased risk of SGA was observed when using the UK-WHO and customised charts as opposed to the ethnic-specific chart, while the opposite was apparent when classifying LGA infants. However, the predictive utility of all three charts to identify adverse clinical outcomes was poor, with only the prediction of shoulder dystocia achieving an AUROC>0.62 on all three charts.

CONCLUSIONS

Despite being recommended in national clinical guidelines, the UK-WHO and customised birth weight charts perform poorly at identifying infants at risk of adverse neonatal outcomes. Being small or large may increase the risk of an adverse outcome; however, size alone is not sensitive or specific enough with current detection to be useful. However, a significant amount of missing data for some of the outcomes may have limited the power needed to determine true associations.

The relationship between early life modifiable risk factors for childhood obesity, ethnicity and body mass index at age 3 years: findings from the Born in Bradford birth cohort study

Background

Many modifiable risk factors in early infancy have been shown to be associated with childhood overweight and obesity. These risk factors have not been studied within children of South Asian origin in the UK. The aims of this paper are to describe differences in the prevalence of modifiable risk factors for childhood obesity between children of White British and Pakistani origin and investigate the association between these risk factors and childhood BMI measured at age 3 years. We used data from a sub-study of the Born in Bradford birth cohort with detailed follow-up visits throughout early childhood. 987 participants with a BMI measurement at age 3 were included; 39% were White British, 48% were of Pakistani origin and 13% were of other ethnicities. Linear and Poisson regression models were used to assess the association between risk factors and two outcomes at age 3; BMI z-scores and child overweight.

Results

Compared to Pakistani mothers, White British mothers were more likely to smoke during pregnancy, have higher BMI, breastfeed for a shorter duration and wean earlier, while Pakistani mothers had higher rates of gestational diabetes and were less active. There was no strong evidence that the relationship between risk factors and BMI z-score differed by ethnicity. There were associations between BMI z-score and maternal smoking (mean difference in BMI z-score 0.33 (95% CI 0.13, 0.53)), maternal obesity (0.37 (0.19, 0.55)), indulgent feeding style (0.15 (−0.06, 0.36)), lower parental warmth scores (0.21 (0.05, 0.36)) and higher parental hostility scores (0.17 (0.01, 0.33)). Consistent associations between these risk factors and child overweight were found. Mean BMI and the relative risk of being overweight were lower in children of mothers with lower parental self-efficacy scores and who watched more hours of TV. Other risk factors (gestational diabetes, child diet, child sleep, child TV viewing and maternal physical activity) were not associated with BMI.

Conclusions

Whilst the prevalence of risk factors that have been associated with childhood greater BMI differ between White British and Pakistani the magnitude of their associations with BMI are similar in the two groups.

Electronic supplementary material

The online version of this article (doi:10.1186/s40608-015-0037-5) contains supplementary material, which is available to authorized users.

Ethnic and sex differences in skeletal maturation among the Birth to Twenty cohort in South Africa

AIM

To examine ethnic and sex differences in the pattern of skeletal maturity from adolescence to adulthood using a novel longitudinal analysis technique (SuperImposition by Translation And Rotation (SITAR)).

SETTING

Johannesburg, South Africa.

PARTICIPANTS

607 boys and girls of black as well as white ethnicity from the Birth to Twenty bone health study, assessed annually from 9 to 20 years of age.

OUTCOME MEASURE

Bone maturity scores (Tanner-Whitehouse III radius, ulna, and short bones (TW3 RUS)) assessed longitudinally from hand-wrist radiographs were used to produce individual and mean growth curves of bone maturity and analysed by the SITAR method.

RESULTS

The longitudinal analysis showed that black boys matured later by 7.0 SE 1.6 months (p<0.0001) but at the same rate as white boys, whereas black girls matured at the same age but at a faster rate than white girls (by 8.7% SE 2.6%, p=0.0007). The mean curves for bone maturity score consistently showed a midpubertal double kink, contrasting with the quadratic shape of the commonly used reference centile curves for bone maturity (TW3).

CONCLUSIONS

Skeletal maturity was reached 1.9 years earlier in girls than boys, and the pattern of maturation differed between the sexes. Within girls, there were no ethnic differences in the pattern or timing of skeletal maturity. Within boys, however, skeletal maturity was delayed by 7 months in black compared with white ethnicity. Skeletal maturation, therefore, varies differentially by sex and ethnicity. The delayed maturity of black boys, but not black girls, supports the hypothesis that boys have greater sensitivity to environmental constraints than girls.

Agreement between routine and research measurement of infant height and weight

In many countries, routine data relating to growth of infants are collected as a means of tracking health and illness up to school age. These have potential to be used in research. For health monitoring and research, data should be accurate and reliable. This study aimed to determine the agreement between length/height and weight measurements from routine infant records and researcher-collected data.

METHODS

Height/length and weight at ages 6, 12 and 24 months from the longitudinal UK birth cohort (born in Bradford; n=836-1280) were compared with routine data collected by health visitors within 2 months of the research data (n=104-573 for different comparisons). Data were age adjusted and compared using Bland Altman plots.

RESULTS

There was agreement between data sources, albeit weaker for height than for weight. Routine data tended to underestimate length/height at 6 months (0.5 cm (95% CI -4.0 to 4.9)) and overestimate it at 12 (-0.3 cm (95% CI -0.5 to 4.0)) and 24 months (0.3 cm (95% CI -4.0 to 3.4)). Routine data slightly overestimated weight at all three ages (range -0.04 kg (95% CI -1.2 to 0.9) to -0.04 (95% CI -0.7 to 0.6)). Limits of agreement were wide, particularly for height. Differences were generally random, although routine data tended to underestimate length in taller infants and underestimate weight in lighter infants.

CONCLUSIONS

Routine data can provide an accurate and feasible method of data collection for research, though wide limits of agreement between data sources may be observed. Differences could be due to methodological issues; but may relate to variability in clinical practice. Continued provision of appropriate training and assessment is essential for health professionals responsible for collecting routine data.

The prevalence of tail injuries in working and non-working breed dogs visiting veterinary practices in Scotland

The aim of this paper was to estimate the prevalence of tail injuries that required veterinary examination in different breeds of dog in Scotland. The study population included all dogs that had visited one of 16 veterinary practices located in Scotland between 2002 and early 2012. The overall prevalence of tail injuries in dogs visiting one of the 16 veterinary practices was 0.59 per cent. The prevalence of tail injuries in dogs of working breeds was estimated to be 0.90 per cent. Working dog breeds that were examined by a veterinary surgeon were at a significantly greater risk of sustaining a tail injury than non-working breeds (P<0.001). To prevent one such tail injury in these working breeds approximately 232 dogs would need to be docked as puppies. To prevent one tail amputation in spaniels, 320 spaniel puppies would need to be docked. Spaniels presented after January 2009 were 2.3 times more likely to have a tail injury than those presented before April 29, 2007 (date of the legislation that banned tail docking in Scotland). Given the results of this and the accompanying paper it may be appropriate to consider changes to the current legislation for specific breeds of working dogs.

Assessing community readiness for overweight and obesity prevention in pre-adolescent girls: a case study

BACKGROUND

Childhood overweight and obesity is a global public health concern. For girls in particular, being overweight or obese during pre-adolescence (aged 7-11 years) has intergenerational implications for both the mother and her future offspring. In the United Kingdom (UK) there is increasing interest in community targeted interventions but less is known about how to tailor these approaches to the needs of the community. This study applied the Community Readiness Model (CRM), for the first time in the UK, to demonstrate its applicability in designing tailored interventions.

METHODS

Community readiness assessment was conducted using semi-structured key informant interviews. The community's key informants were identified through focus groups with pre-adolescent girls. The interviews addressed the community's efforts; community knowledge of the efforts; leadership; community climate; community knowledge of the issue and resources available to support the issue. Interviews were conducted until the point of theoretical saturation and questions were asked separately regarding physical activity (PA) and healthy eating and drinking (HED) behaviours. The interviews were transcribed verbatim and were firstly analysed thematically and then scored using the assessment guidelines produced by the CRM authors.

RESULTS

Readiness in this community was higher for PA than for HED behaviours. The lowest scores related to the community's 'resources' and the 'community knowledge of the issue'; affirming these two issues as the most appropriate initial targets for intervention. In terms of resources, there is also a need for resources to support the development of HED efforts beyond the school. Investment in greater physical education training for primary school teachers was also identified as an intervention priority. To address the community's knowledge of the issue, raising the awareness of the prevalence of pre-adolescent girls' health behaviours is a priority at the local community level. Inconsistent school approaches contributed to tensions between schools and parents regarding school food policies.

CONCLUSIONS

This study has identified the readiness level within a UK community to address the behaviours related to overweight and obesity prevention in pre-adolescent girls. The focus of an intervention in this community should initially be resources and raising awareness of the issue within the community.

Multi-level modelling of longitudinal child growth data from the Birth-to-Twenty Cohort: a comparison of growth models

Background: Different structural and non-structural models have been used to describe human growth patterns. However, few studies have compared the fitness of these models in an African transitioning population.

Aim: To find model(s) that best describe the growth pattern from birth to early childhood using mixed effect modelling.

Subjects and methods: The study compared the fitness of four structural (Berkey-Reed, Count, Jenss-Bayley and the adapted Jenss-Bayley) and two non-structural (2nd and 3rd order Polynomial) models. The models were fitted to physical growth data from an urban African setting from birth to 10 years using a multi-level modelling technique. The goodness-of-fit of the models was examined using median and maximum absolute residuals, Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC).

Results: There were variations in how the different models fitted to the data at different measurement occasions. The Jenss-Bayley and the polynomial models did not fit well to growth measurements in the early years, with very high or very low percentage of positive residuals. The Berkey-Reed model fitted consistently well over the study period.

Conclusion: The Berkey-Reed model, previously used and fitted well to infancy growth data, has been shown to also fit well beyond infancy into childhood.

Bone geometry according to menstrual function in female endurance athletes

Athletes have higher bone mineral density (BMD) relative to nonathletes. In amenorrheic athletes BMD may be compromised by estrogen deficiency, but it is unknown whether this is accompanied by structural differences. We compared femoral neck bone geometry and density of a-/oligomenorrheic athletes (AAs), eumenorrheic athletes (EAs), and eumenorrheic controls (ECs). We recruited 156 women: (68 endurance athletes and 88 controls). Femoral neck BMD, section modulus (Z), and width were measured using dual-energy X-ray absorptiometry. Menstrual function was assessed by questionnaire and classified as EA (≥10 periods/year) or AA (≤9 periods/year): 24 athletes were AA and 44 EA. Femoral neck BMD was significantly higher in EA than AA (8 %, difference) and EC (11 % difference): mean [SE] 1.118 [0.015], 1.023 [0.020] and 0.999 [0.014] g cm(-2), respectively; p < 0.001. Z was significantly higher in EA than EC (11 % difference): EA 667 [19], AA 625 [21], and EC 592 [10] cm(3); p < 0.001. Femoral neck width did not differ between groups. All differences persisted after adjustment for height, age, and body mass. The higher femoral neck Z and BMD in athletes, despite similar width, may indicate that exercise-related bone gains are endosteal rather than periosteal. Athletes with amenorrhea had smaller increments in bone mass rather than structural adaptation. The maintained femoral neck width in controls may be an adaptive mechanism to conserve bone strength in bending despite inactivity-related bone decrement.

UK-born Pakistani-origin infants are relatively more adipose than white British infants: findings from 8704 mother-offspring pairs in the Born-in-Bradford prospective birth cohort

Background

Previous studies have shown markedly lower birth weight among infants of South Asian origin compared with those of White European origin. Whether such differences mask greater adiposity in South Asian infants and whether they persist across generations in contemporary UK populations is unclear. Our aim was to compare birth weight, skinfold thickness and cord leptin between Pakistani and White British infants and to investigate the explanatory factors, including parental and grandparental birthplace.

Methods

We examined the differences in birth weight and skinfold thickness between 4649 Pakistani and 4055 White British infants born at term in the same UK maternity unit and compared cord leptin in a subgroup of 775 Pakistani and 612 White British infants.

Results

Pakistani infants were lighter (adjusted mean difference −234 g 95% CI −258 to −210) and were smaller in both subscapular and triceps skinfold measurements. The differences for subscapular and triceps skinfold thickness (mean z-score difference −0.27 95% CI −0.34 to −0.20 and −0.23 95% CI −0.30 to −0.16, respectively) were smaller than the difference in birth weight (mean z-score difference −0.52 95% CI −0.58 to −0.47) and attenuated to the null with adjustment for birth weight (0.03 95% CI −0.03 to 0.09 and −0.01 95% CI −0.08 to 0.05, respectively). Cord leptin concentration (indicator of fat mass) was similar in Pakistani and White British infants without adjustment for birth weight, but with adjustment became 30% higher (95% CI 17% to 44%) among Pakistani infants compared with White British infants. The magnitudes of difference did not differ by generation.

Conclusions

Despite being markedly lighter, Pakistani infants had similar skinfold thicknesses and greater total fat mass, as indicated by cord leptin, for a given birth weight than White British infants. Any efforts to reduce ethnic inequalities in birth weight need to consider differences in adiposity and the possibility that increasing birth weight in South Asian infants might inadvertently worsen health by increasing relative adiposity.

Describing differences in weight and length growth trajectories between white and Pakistani infants in the UK: analysis of the Born in Bradford birth cohort study using multilevel linear spline models

OBJECTIVE

To describe the growth pattern from birth to 2 years of UK-born white British and Pakistani infants.

DESIGN

Birth cohort.

SETTING

Bradford, UK.

PARTICIPANTS

314 white British boys, 383 Pakistani boys, 328 white British girls and 409 Pakistani girls.

MAIN OUTCOME MEASURES

Weight and length trajectories based on repeat measurements from birth to 2 years.

RESULTS

Linear spline multilevel models for weight and length with knot points at 4 and 9 months fitted the data well. At birth Pakistani boys were 210 g lighter (95% CI -290 to -120) and 0.5 cm shorter (-1.04 to 0.02) and Pakistani girls were 180 g lighter (-260 to -100) and 0.5 cm shorter (-0.91 to -0.03) than white British boys and girls, respectively. Pakistani infants gained length faster than white British infants between 0 and 4 months (+0.3 cm/month (0.1 to 0.5) for boys and +0.4 cm/month (0.2 to 0.6) for girls) and gained more weight per month between 9 and 24 months (+10 g/month (0 to 30) for boys and +30 g/month (20 to 40) for girls). Adjustment for maternal height attenuated ethnic differences in weight and length at birth, but not in postnatal growth. Adjustment for other confounders did not explain differences in any outcomes.

CONCLUSIONS

Pakistani infants were lighter and had shorter predicted mean length at birth than white British infants, but gained weight and length quicker in infancy. By age 2 years both ethnic groups had similar weight, but Pakistani infants were on average taller than white British infants.

A systematic review to determine the effectiveness of interventions designed to prevent overweight and obesity in pre-adolescent girls

Childhood overweight/obesity is recognized as an increasing health problem. The objective of this review was to determine the effectiveness of interventions designed to prevent overweight and obesity in pre-adolescent girls. The papers included were those studying children (must include results for girls) from within the 7-11 years age range from any country and ethnic background. The included interventions lasted at least 12 weeks and modified a combination of nutrition, physical activity, knowledge, attitudes or health-related behaviours associated with the development of childhood overweight and obesity. Effect sizes were calculated where possible using Cohen's classifications of small (0.2-0.5), medium (0.5-0.8) and large (>0.8) effect sizes. Thirty studies met the inclusion criteria of which four were cluster randomized controlled trials, 14 were randomized controlled trials, 11 were controlled trials and one was a cohort pre-post trial. There were four weak, 11 moderate and 15 strong quality studies. Eleven studies were considered short term and 19 long term (≥12 months). There were 66 effect sizes less than 0.2, 56 categorized as low, 16 as medium and two as high. There is the potential for interventions aimed at pre-adolescent girls to reduce the risk factors associated with childhood overweight and obesity, although the sustainability of the effects of such interventions is less clear.

Small fibre neuropathy: role in the diagnosis of diabetic sensorimotor polyneuropathy

Small fibres constitute 70-90% of peripheral nerve fibres and regulate several key functions such as tissue blood flow, temperature and pain perception as well as sweating, all of which are highly relevant to the clinical presentation and adverse outcomes associated with foot ulcerations in patients with diabetes. Recent studies demonstrated significant abnormalities in the small fibres in subjects with impaired glucose tolerance and diabetes, despite normal electrophysiology, suggesting that the earliest nerve fibre damage is to the small fibres. Unfortunately, guidelines and consensus statements focus on large fibres and continue to advocate electrophysiology as a diagnostic modality and as a primary end point for the assessment of therapeutic benefit. (In part, this reflects the difficulties in quantifying small fibre dysfunction and damage.) We have therefore critically assessed currently available techniques that measure small fibre dysfunction in diabetic neuropathy, using quantitative sensory and sudomotor testing. We have assessed the role of identifying structural damage by quantifying intraepidermal nerve fibre density in skin biopsies and corneal nerve morphology using corneal confocal microscopy. Finally, we propose a definition for diabetic neuropathy that incorporates small fibre damage.

Bone mass and bone size in pre- or early pubertal 10-year-old black and white South African children and their parents

Genetic factors are thought to maintain bone mass in socioeconomically disadvantaged black South Africans. We compared bone mass between environmentally disadvantaged black and advantaged white children and their parents, after determining the most appropriate method by which to correct bone mineral content (BMC) for size. We collected data from 419 healthy black and white children of mean age 10.6 years (range 10.0-10.9), 406 biological mothers, and 100 biological fathers. Whole-body, femoral neck, lumbar spine, and mid- and distal one-third of radius bone area (BA) and BMC were measured by dual-energy X-ray absorptiometry. Power coefficients (PCs) were calculated from the linear-regression analyses of ln(BMC) on ln(BA) and used to correct site-specific BMC for bone size differences. Heritability (½h(2), %) by maternal and paternal descent was estimated by regressing children's Z scores on parents' Z scores. Correcting BMC for height, weight, and BA(PC) accounted for the greatest variance of BMC at all skeletal sites. In so doing, BMC in blacks was up to 2.6 times greater at the femoral neck and lumbar spine. Maternal and paternal heritability was estimated to be ~30% in both black and white subjects. These results may in part explain the lower prevalence of fragility fractures at the hip in black South African children when compared to whites. Heritability was comparable between environmentally disadvantaged black and advantaged white South African children and similar to that reported for Caucasians in other parts of the world.

Temporal and environmental patterns of sedentary and active behaviors during adolescents' leisure time

BACKGROUND

There is great interest in young people's overweight and obesity. Few data, however, describe when sedentary and physically active behaviors are likely to occur during the day or how these behaviors are related to location.

PURPOSE

The purpose of this study was to describe sedentary and active leisure-time behaviors of adolescents across the day and setting.

METHOD

Adolescents (male n = 579, female n = 967; aged 13-16 years) completed time-use diaries for three weekdays and one weekend day. At 15 min intervals, participants recorded what they were doing and where they were.

RESULTS

TV viewing and sports/exercise peaked at different times in the day, although TV viewing was two to three times more likely to occur than sports/exercise. TV viewing was most likely to occur during the middle to late evening. The playing of computer games was low, particularly for girls. Weekend data showed TV viewing was the most reported activity throughout the day. For boys, "being in the garden" was highly predictive of engaging in sports/exercise, but this declined rapidly with age. Motorized travel to school was reported twice as often as active travel.

CONCLUSION

Momentary assessments of behavior, in conjunction with contemporaneous reports of environmental factors, describe important patterns of leisure-time active and sedentary behaviors in youth.

[A non invasive method for assessing sexual development at adolescence]

INTRODUCTION

Observational assessments of puberty that invades the adolescent's privacy are not acceptable for research in population groups. Results based on self assessment have been variable, and in many cases poor.

OBJECTIVES

To evaluate the validity of a questionnaire with simple questions addressed to assess early, intermediate and advanced puberty periods rather than specific stages.

MATERIAL AND METHODS

In an outpatient clinic at the Service of Adolescence of a public hospital, 188 and 142 healthy girls and boys aged 8-18 years, and 36 girls and boys aged 8-9 years attending a public school were studied. Adolescents attended the Service for the first time. Those with chronic diseases were excluded from the study. Children answered the questionnaire before entering the doctor's office, where a trained professional clinically assessed their puberal development (Tanner's stage). The questionnaire was previously tested in 30 adolescents.

RESULTS

The highest concordance were found in the questions: "Have you started puberty?", with Tanner's stages III, IV or V (Kappa value= 0.60); "Have you already had your first menstrual period?" with stages IV-V (K= 0.69); and "Do you shave?" with stages IV-V (K= 0.66). In most cases, these questions showed high (> or = 0.80) sensitivity and specificity for detecting the mentioned puberty periods.

CONCLUSIONS

The method showed to be reliable, and its further evaluation in a non medical setting (schools, households, etc.) is recommended.

Rapid infant weight gain and advanced skeletal maturation in childhood

OBJECTIVE

To test the hypothesis that rapid infant weight gain is associated with advanced skeletal maturity in children from the United States and South Africa.

STUDY DESIGN

Longitudinal data from 467 appropriate-for-gestational-age infants in the Fels Longitudinal Growth Study (Dayton, Ohio) and 196 appropriate-for-gestational-age infants in the Birth to Twenty birth cohort study (Johannesburg, South Africa) were used. Multiple linear regression models tested the association between internal SD score change in weight from 0 to 2 years and relative skeletal age at 9 years, adjusting for body mass index, stature, and other covariates.

RESULTS

In both studies, faster infant weight gain was associated with more advanced skeletal maturity (approximately 0.2 years or 2.4 months per SD score) at age 9 years (P <.0001-.005), even when adjusting for the positive associations of both birth weight and body mass index at age 9 years. This effect appeared to be accounted for by the greater childhood stature of subjects with more rapid infant weight gain.

CONCLUSIONS

Relatively rapid infant weight-gain is associated with advanced skeletal development in late childhood, perhaps via effects on stature.

BASIC programs for the assessment of skeletal maturity and the prediction of adult height using the Tanner-Whitehouse method

A family of BASIC microcomputer programs is described that carry out the computations required for the assessment of skeletal maturity and the prediction of adult height according to the Tanner- Whitehouse techniques. These programs significantly reduce the tedious computations required for these assessments and present final data in a comprehensible format. Both the original, Mark 1, and the newer, Mark 2, prediction methods are included because even though the latter is intended to replace the former, this replacement will naturally take some time and comparability studies will inevitably be undertaken. The programs are written in Applesoft BASIC but may be easily modified for other microcomputers or main-frames with the facility for BASIC compilation.

Socio-economic predictors of stunting in preschool children--a population-based study from Johannesburg and Soweto

BACKGROUND

Stunting continues to be a child public health concern in many African countries, including South Africa. This study uses data from the Birth to Twenty study, held in Johannesburg, to investigate a range of household-level socioeconomic and social support predictors of stunting in children aged less than 30 months.

DESIGN

Logistical regression models were constructed using a conceptual framework to investigate the association between early life measures of socio-economic status and stunting (<--2 standard deviations from the WHO (2006) standard), using data collected in the Birth to Twenty study.

RESULTS

Stunting prevalence was 18.0% (213/1 186). In unadjusted analyses, numerous socio-economic status exposures showed significant associations with stunting; however, in final multivariable models, decreased likelihood of stunting was seen in children born to mothers who were employed (adjusted odds ratio (AOR) = 0.60, 95% confidence interval (CI) 0.40-0.88), those with fathers who had completed secondary school (AOR = 0.59, 95% CI 0.40-0.85), and whose parents employed a domestic worker (AOR = 0.40, 95% CI 0.19-0.83), while increased likelihood of stunting was seen in male children (AOR = 1.40, 95% CI 1.03-1.91), and those born of low birth weight (AOR = 2.56, 95% CI 1.54-4.26).

CONCLUSIONS

Stunting and child malnutrition remain policy priorities for the South African Department of Health, and this study suggests that policies that aim to increase parental education level and reduce unemployment or target additional support to families with low education or unemployed parents may reduce stunting in preschool-age children in this setting.

Implications of adopting the WHO 2006 Child Growth Standards: case study from urban South Africa, the Birth to Twenty cohort

BACKGROUND

The World Health Organization (WHO) recently developed growth standards to overcome the limitations of previous references.

AIM

The aim of this study was to compare the growth patterns of a cohort of children using the National Centre for Health Statistics (NCHS), the Centre for Disease Control (CDC), and WHO 2006 references/standards, and to evaluate the implications of adopting WHO standards.

SUBJECTS AND METHODS

Using growth data (0-5 years) from the 1990 South African Birth to Twenty cohort in Johannesburg-Soweto, Z-scores were derived for weight-for-age, length/height-for age, and weight-for-length/height from the NCHS and CDC references, and WHO 2006 standards.

RESULTS

The pattern of mean Z-score change observed when applying the NCHS and CDC references was similar to one another, but different to that obtained when using the WHO 2006 standard. WHO 2006 identified children as being generally more stunted and more overweight.

CONCLUSION

Discourse on the implementation of WHO 2006 and the impact on the primary health care system and public health monitoring in South Africa is needed, and sufficient planning is critical around not only the implementation of WHO 2006 but also maintaining comparability with historical malnutrition data.

Polymer Flood Application to Improve Heavy Oil Recovery at East Bodo

Abstract

The East Bodo, Lloydminster SS heavy oil pool has been exploited using primary recovery and waterflood. IOR screening showed that a polymer flood would be a preferred IOR technique. Subsequent coreflood tests indicated that the polymer flood could recover 20% OOIP incremental oil, after waterflooding, to a 95% water cut. Data gathered from the coreflood was used to fine tune the reservoir simulation model to help design the pilot and predict potential economic reserve capture for a commercial field-wide polymer flood. Subsequently, a pilot was initiated. During the pilot operation, achieving the target polymer viscosity, dependant on water quality, proved to be a significant challenge. Early field response is being observed through an increase in injection pressure, reduced water cut and polymer breakthrough. Further positive response of this polymer pilot allows for the expansion of the polymer flood technology to other parts of this reservoir; some with bottomwater and gas cap. This paper reviews the progress of the East Bodo polymer flood, from laboratory concept to working field application, in four major steps:IOR screening using simulations and coreflooding,field pilot design/implementation,pilot performance, andnext steps.

Introduction

Pengrowth has targeted East Bodo (Alberta side) and Cosine (Saskatchewan side) for waterflood optimization and subsequent enhanced oil recovery applications. Currently, the most practical EOR technology for this heavy oil reservoir seems to be the polymer flood technology in combination with horizontal wells. Several investigators(1–4) have demonstrated the potential of the polymer flood technology for improved oil recovery in heavy oil reservoirs.

The East Bodo/Cosine Reservoir produces from the Lloydminster Formation, which is part of the Lower Cretaceous Mannville Group. Pengrowth provided some of the reservoir characteristics, as summarized in Table 1. This particular reservoir is separated into two parallel lobes trending North/West to South/East.

To complicate matters, local gas caps are found primarily on the Saskatchewan side of the reservoir. Thus, the current waterflood patterns are located on the Alberta side. In the future, optimized waterflood and EOR schemes need to include those parts of the reservoir which are overlain by gas caps or influenced by bottomwater. A plan of progression aligned with the priorities of Pengrowth was laid out as follows:Optimize existing waterflood;Step out waterflood into limited gas cap areas;Then, target areas with a more extensive gas cap;Determine enhanced waterflood potential, for instance polymer flood; andArrange well patterns to benefit both waterflood and subsequent EOR process.

IOR Screening

Several IOR technologies were considered for application in the East Bodo Field. What follows is a list of IOR processes that were initially considered, but screened out after technical or economical issues could not be overcome.Thermal Recovery: Pay is too thin - heat loss to overburden is too large; oil not viscous enough to form a stable steam chamber; fireflood has potential, but a previous pilot on a neighbouring McLaren pool yielded poor results.

The prevalence of sedentary behavior and physical activity in leisure time: A study of Scottish adolescents using ecological momentary assessment

OBJECTIVE

To report time and prevalence of leisure time sedentary and active behaviors in adolescents.

METHOD

Cross-sectional, stratified, random sample from schools in 14 districts in Scotland, 2002-03, using ecological momentary assessment (n=385 boys, 606 girls; mean age 14.1 years; range 12.6-16.7 years). This is a method of capturing current behavioral episodes. We used 15 min time intervals.

RESULTS

Television viewing occupied the most leisure time. The five most time consuming sedentary activities occupied 228 min per weekday and 396 min per weekend day for boys, and 244 min per weekday and 400 min per weekend day for girls, with TV occupying one-third to one-half of this time. In contrast, 62 min was occupied by active transport and sports/exercise per weekday and 91 min per weekend day for boys, with 55 min per weekday and 47 min per weekend day for girls. A minority watched more than 4 h of TV per day, with more at weekends. Other main sedentary behaviors for boys were homework, playing computer/video games, and motorised transport and, for girls, homework, motorised transport, and sitting and talking.

CONCLUSION

Scottish adolescents engage in a variety of sedentary and active behaviors. Research into sedentary behavior must assess multiple behaviors and not rely solely on TV viewing.